Mirissa is in the southern province of Sri Lanka.
Mirissa is a beautiful little fishing village with a nice beach and two surfing points. One for advanced surfers, and one for intermediate ones.
It has a slightly less tourist-friendly and more lawless reputation than the Southwest; the odd situations that tourists were threatened by locals (esp. with tourist ladies involved), and/or rape drugs (drink spiking) used, and/or restaurants in turn refusing locals as in these cases police cannot protect the restaurants against the local mafia, are all in the Deep South. It’s all isolated and rare, but more caution especially by females is needed here than in e.g. Hikka. See e.g. that some restaurants even have public banners saying locals are not welcome; staff to remove any Sri Lankan coming in despite these banners with force and refusing to serve a order. 
Take bus heading to Matara or Tangalle from Fort in Colombo and ask to get out in Mirissa. A/C costs 370 Rupees. Regular costs 250 Rupees. Depending on when you go, a trip will take between 3.5 and 5 hours.
Alternatively, you can take the train from Colombo Fort to Weligama (7 km from Mirissa) and then go by bus (20 Rupees in 2014) or tuk tuk (300 Rupess in 2014). A 2nd class train ticket costs 220 Rupees. The train schedule is available here. Trips take between 2.5 and 3.5 hours (depending on the train).
Mirissa is a small village, you can basically get everywhere by feet.
Walking. Cycling. Motorbiking. Tuk Tuk. Available to rent everywhere.
Buddhist temple. Fisherman harbour. Beach.
Surfing. Bodyboarding. Whale watching. Swimming. Snorkelling. Sailing. Ayurvedic treatments. Party.
- Whale and dolphin watching: there are many companies with different prices (2000-6000 LKR), but in the end all of them are similar, and you will be surrounded by another 12 boats while hunting the animals. You can easily get good views of dolphins, as they will be in a big group jumping out of the water for a long time, but don't expect much from the whales: they are elusive, and you'll most likely only see a bit of their back for a brief second when they come out for air. The boats will chase them around until you get four or five of these sightings, and then head back home. If the engine doesn't fail, you'll be boarding at 6:30, leave the harbour at 7:00, and be back by 11:00. Some boats have plastic chairs, others have benches, others have mattresses on the upper deck floor. Check the boat at the harbour, ask how many people will be on board, and avoid overcrowding. All of them include a cup of coffee or tea, a small bottle of water, some breakfast (jam sandwich), bananas, pineapple and watermelon.
- Diving: talked to a local divemaster that has been diving here for more than 20 years, and told me that the chances of seeing whales while diving are nil. You can always go deep into the blue and wait, but more often than not you'll just spend a boring hour without seeing anything. He confessed that it's just a lot of marketing.
- Raja & The Whales, Mirissa Harbour, ☎ +94 71 333 1811, . Great company, which provides sustainable whale watching in Mirissa. 6000 LKR (Dec 2015). edit
- Mirissa Water Sports, Harbour road, Mirissa, ☎ +94 77 359 77 32. The pioneers of whale watching in Sri Lanka and employs youth people who were affected by the tsunami in 2004. edit
- Mirissa Moorings, Harbour road, Mirissa, ☎ +94 772220967. Mirissa Moorings is the premiere boat charter mooring facilities and services in Mirissa offering sailing trips on 6,5 m MiniBee boats (manufactured in Sri Lanka) to local and foreign tourists. You can rent boats with or without a skipper if you have a valid/international sail license. edit
Most of the shops are located on the main Galle-Matara road. Some shops you can also find on Paradise Road.
Many different restaurants on the beach. Cheaper but still very tasty options are the Roti shops more inland. For budget travelers, food is notably more expensive in Mirissa than usual, with a basic fried rice no cheaper than 300 LKR and kottu starting at 550LKR...
- Dewmini Roti Shop, ☎ 0715162604. 7am-10pm. Very nice, quiet place to have a drink or taste the delicious fresh rotis. Little inland (follow small road next to internet place on the main street and look out for the signposting). edit
In the beach bars around the beach.
- Ayodya Resort, (Main Road near à bus stop). Operated by Sri Lankan famille, the house is build with some cozy rooms. 4 rooms is available with fan, hot shower, clean and spacious... Free good Wi-Fi in public area and some rooms. Kitchen available. From 1000 for à double room. edit
- Ancient Tree Guesthouse, Yaddehigoda, Bandaramulla (Up a small road running perpendicular away from the east end of the beach, by the pedestrian crossing), ☎ +94778595501, . In a quiet, leafy area behind the hilltop temple. This small family-run guesthouse is affordable, with pleasant hosts and wonderful food edit
- ExtremeHost Guest house, 373/A/1, Udupila, Mirissa, ☎ +94711218810. checkin: 2am; checkout: 11am. Extreme Host Guest house ideally situated a short distance away from the Beautiful Mirissa Beach. Pubs, restaurants, and Shops are stroll away. (5.939042,80.460607) edit
- First Mirissa Beach Hostel (Mirissa Beach Hostel First), Hostel First Mirissa Beach, Beach Side Road, Mirissa, Sri Lanka (If you come by bus from Colombo to Matara, ask the driver to let you off near Beachside Road in Mirissa. Follow the main road until you see Beachside Road and an ATM on the left side (there's only 2 ATMs in Mirissa). Then walk along Beachside Road and you will soon see our hostel on your left hand side.), ☎ +94 (0)76 7986 788 ([email protected]), . Dorm US $10, private rooms $30. (5.9458,80.4577) edit
- Jumera Villa, Mihiriwella road (On the corner northwest from Harbour road), ☎ +94771992089 ([email protected]). Three very nice rooms with king bed and private bathroom. Two rooms with AC and one with fan, all with mosquito net. The house has a nice garden, and is in a very quiet area. The owner is very friendly, and her neighbour can arrange cheaper whale watching trips. Fan room from 1000LKR (Dec 2015). edit
- Lantern Boutique Hotel, 71, Galle Road, Kamburugamauwa, Mirissa 81750, ☎ +94 414 938 356 ([email protected]), . checkin: 2pm; checkout: 12pm. This villa features six large well-appointed bedrooms with neatly decorated private lounge spaces with lounge chairs to allow you to enjoy the scenery around. Starting from USD 190. edit
- Mirissa Beach House, Beach side / Paradise road (At the headland end of Mirissa Beach.), ☎ +971566832281, . checkin: 2pm; checkout: 11am. A private Villa with room for up to 6 people. For privacy we only rent to one group to at a time. 40 meters from the beautiful Mirissa beach, bars and restaurants. Great outside area for relaxing after a day in the sun. Hot water shower and comfortable clean beds with mosquito nets. The house has 2 double beds and a adult length double bunk. Strong fans cool all sleeping and sitting areas. House has tea, coffee and toast facilities with a refrigerator but not full kitchen. Downstairs there is a great BBQ area if you feel like cooking some of the local seafood. Sunbeds are available in the garden and downstairs if you feel like relaxing outside. low season 120 USD a night. (5.943806,80.456212) edit
- Sri Sharavi Beach Villas & Spa, 153 Km Post, Ruhunupura, Thalaramba, Kamburugamuwa, Mirissa, ☎ +94417451090, . checkin: 2pm; checkout: 12pm. A luxury boutique hotel in the Mirissa beachfront. The hotel consists of standard rooms, suites and villas. It also offers dining and spa facilities. Rates Starting from USD 150. (5.946670,80.487137) edit
- Stella Beach Villa, ☎ (+44) 203 411 3675, . Stella Beach Villa is situated next to Mirissa beach and is at the top end of the market for villa rentals. Sleeping up to eight guests in four bedrooms, the villa has its own 400 metre stretch of private beach and a 20 metre pool. However, in low season the price of the villa can be as little as 500 USD per night. edit
- Teviedu Guest House, no324, uswatta, udupila, mirissa, ☎ +94715927833. Very nice place run by a local family. Provides the best view in Mirissa. Rooms starting from about 700 Rupies off season. 10 minutes off the beach and surf point (very right side on the beach when you watch the sea - up the hill). edit
- The Beach House, 41, Galle Road, Kamburugamuwa, Mirissa, ☎ +94 11 4790555 ([email protected]), . checkin: 2pm; checkout: 12pm. A beachside property in Mirissa offering a range of suites. The property is complete with ocean view rooms and pool villas with luxury dining options. Starting from USD 200. edit
- Ubuntu Beach Villas, 53A, Galle Road, Kamburugamauwa, Mirissa 81750, ☎ +94 414 938 356 ([email protected]), . checkin: 2pm; checkout: 12pm. Two standalone villas situated 500 meters away from each other along the beach. Each villa consists of 8 private rooms with ocean views and garden views. Starting from USD 190. edit
Many buses go through the main road both sides. It's possible to catch buses from Galle, Matara, Colombo...
Stand near bus stop and ask the driver or local people.