Nuuksio National Park
Covering an area of 45 square kilometers, Nuuksio is one of the smaller national parks in Finland, but also one of the best accessible to visitors as a day-trip from Helsinki. The main attraction of Nuuksio is a broad selection of different types of forest, lakes, ponds, and some swamps. The pine forests near Solvalla and the different forest types near Haukkalampi and Mustalampi are particularly attractive.
Established only in 1994, Nuuksio is one of Finland's newest national parks, set up to ensure that a piece of pristine wilderness is kept within striking distance of the capital. Its location so close to a major city is unusual, and due mostly to the fact that the rocky and wet terrain was unsuitable for farming or other development.
Nuuksio's landscape is archetypically Finnish: conifer and birch forests, forty-three lakes, small swamps between them and gentle rolling hills, sometimes covered in moss, sometimes with the granite bedrock exposed where the vast ice sheets of the last ice age scraped them clean. There are plenty of quiet spots of beauty, but don't expect jaw-dropping gorges or soaring mountains (good advice for traveling anywhere in Finland, that).
Flora and fauna
The Siberian Flying Squirrel (Liito-orava) is official park emblem, but being nocturnal and living high up in the treetops, it's very difficult to spot. The Haukkalampi info center has an exhibit about the critter and even gives handy tips on how to spot its poo.
Larger mammals are rarely seen. Lynx, fox, hare and deer are present in the southern end of the park.
The adder (viper) is not uncommon in the rocky areas near Solvalla and Mustalampi. These small snakes are venomous, so don't try to catch. Not that you are likely to see them: they tend to escape and hide when approached.
Nuuksio's climate is the same as Helsinki's: cool but relatively sunny and dry springs, lovely yet possibly rainy summers, rainy autumn, cold winters with snow or slush. The high season is obviously summer, although mushroom pickers continue to tramp the trails well into the autumn, and hardcore cross-country skiers venture within in the winter. Late April, May, and early June are excellent times to visit Nuuksio, as it is less likely to rain and there are no or only few mosquitos.
For those coming by car, there are major parking lots at Solvalla, Haukkalampi and Kattila, and lots of other parking possibilities elsewhere. It is a 35 minute drive from the center of Helsinki. Besides car, the other options are bicycle and bus.
The bus services to Nuuksio require a transfer if coming from Helsinki. Check schedules from the route planner  before setting off, as services are quite limited on some routes. The main bus route through Nuuksio goes along the eastern shore of the Nuuksion Pitkäjärvi lake, denoted eastern side of the park below. The most popular parts of the park are accessible from along that bus route.
To get to the eastern side of the park, take the commuter train S, U, E or L from the Central Railway Station to Espoo station, then transfer to bus 245. The Haltia nature centre in Solvalla is the first good point for accessing the area. Get off at Nuuksionpää 2 kilometers after Solvalla/Halti if going to the Haukkalampi area. It's a two-kilometer stroll on the unpaved road to Haukkalampi. If going to the northern parts of Nuuksio, get off the bus at the last stop at Kattila (May-October only).
To get to the southern side of the park at Siikajärvi, take the trains A, E, U, S, L or Y to Leppävaara and transfer to bus 238, 238K or 242. You need good maps and prior planning to enter Nuuksio from here, as the entrance to Nuuksio is poorly marked and there are no park facilities here.
To get the southwestern side of the park, take a bus 280 or 290  from Helsinki City Bus Terminal (Kamppi Center) to Veikkola koulu and take a taxi to last few kilometers north to the park. You can also walk or cycle those quiet village roads. You need good maps and prior planning to enter Nuuksio from here, as the entrance to Nuuksio is poorly marked and there are no park facilities here.
To get to the rarely visited western side of the park, take a bus 280 or 290  from Helsinki City Bus Terminal (Kamppi Center) to Tervalammen kartano and walk several km. You need good maps and prior planning to enter Nuuksio from here, as the entrance to Nuuksio is poorly marked.
To get to the quiet northeastern side of the park, take a bus 346  from Helsinki City Bus Terminal (Kamppi Center) to Pyyslampi. The nature park with its lakes begins right from the southern side of the road.
Most nature excursions by Feel The Nature (see Do) include return transportation from Helsinki City Centre and Espoo.
Entry to the park is free and no special permits are necessary.
Motorized vehicles are prohibited in the park, so most visitors get around is by hiking. The Haukkalampi information cabin (Haukkalammen luontotupa) near the main entrance has simple free maps, or invest €10 in a detailed topographic map of the area. You can also pick up the map at Helsinki tourist info offices.
Bicycling is allowed on 30 km of designated routes, including National Cycle Route 2, 14 km of which passes through the park. Nuuksion Ratsastuskeskus  can arrange horse rides on 22 km of routes as well.
A number of well-signposted trails are available, while hardcore hikers can head out into the bush and stay at one of the many campsites. For the first time visitor, doing the Haukankierros loop and half of Korpinkierros will provide a good representative look (see the Trails section below). Other shorter, less formal walks are easy to do.
The area with the best facilities is Solvalla with its Haltia nature centre, including a cafe and lunch restaurant. The Solvalla area has the most easily accessible paths for walking and biking, and the maps are good. There is a good choice of short and longer walks. This area right east of Haltia/Solvalla is mostly dry pine forest with rocky areas, not much lakes or ponds. This is some of the prettiest pine forest you will see in Nuuksio. The Haltia center is at a scenic location next to the Nuuksion Pitkäjärvi lake. To reach the forest paths from Haltia, walk the steep asphalt road or wooden stairs up to the sports field, a couple of hundred meters from Haltia. Walking paths both north-east and south-east start from behind the field.
The second area for walks and with some facilities is the Haukkalampi lake, with a small hut (Haukanpesä) with coffee and small snacks (open Tuesday to Sunday from 10am until 4:30pm in the summer season June, July, August). From Haukkalampi it is a short 500 meter walk west and and south to the scenic Mustalampi lake. There are campfire facilities, including firewood here. From Mustalampi you can walk about 1.5 kilometers south to the Siikajärvi lake, and catch a different bus toward Espoo centre. Alternatively, you can walk west to Holma-Saarijärvi, and come back the same way.
A third starting point for walks is the end of the Nuuksio main road at Kattila. From Kattila you can walk south 3 kilometers to Haukkalampi. The path starts towards south-west from the parking lot, heading across the pasture with sheep. Walks north from Kattila are first less attractive: the more attractive forest and lake area starts 3 kilometers north at the Iso-Parikas lake. Then you either have to walk further 5 kilometer north to the main road there (large part of which is not in the forest), or walk back the same way.
Picking berries in late summer and mushrooms in the fall are popular activities. Fishing is allowed, although there isn't all that much to catch.
Rock climbing is allowed only at Pitkäjärvi and the eastern Kolmoislammet. Ice climbing is permitted throughout the park.
Cross-country skiing Solvalla has excellent skiing trails much of the winter from January until March.
Downhill skiing is possible at Solvalla-Swinghill on its three small downhill slopes with one lift and a very modest elevation difference of 70 meters. There is snow generally from January to early March. This is some of the best downhill skiing near Helsinki (but unimpressive in comparison to skiing in real mountains like the Alps, or even compared to Lapland.)
Several tour operators specializes in Nuuksio:
Eat, Drink or Buy
There are two cafes in Nuuksio.
Water is available at the Haukkalampi information center. Making an open fire is allowed at the designated fireplaces near the campgrounds, so bring some sausages and have a picnic. Some of the fireplaces are covered and thus usable even when it rains.
Hotel Siikaranta (see below) restaurant offers Finnish-style buffets for hungry hikers, but opening hours are limited.
Several wilderness lodges can be rented cheaply, but they're popular so advance bookings are essential. You will also need to bring your own sleeping bags.
For groups, Green Window (see Do) can also arrange private lodgings elsewhere in the park.
Camping is permitted only in four designated campgrounds in the park. None have any facilities, but open fires are allowed.
Apart from vipers and the very remote chance of meeting a bear, there is little dangerous fauna in the park. Thanks to the swampy terrain, mosquitoes can be a (minor) nuisance (from end of June until August). Remember to check yourself after hike for possible ticks (risk of disease). Stay on the main trails if you don't have a compass, map and orienteering experience. If you get lost, remember that Nuuksio is surrounded by major road on all sides, and by walking straight in any chosen direction will take you out of the park in at most 3 hours, and probably must sooner.