Classic Tokyo, Modern Tokyo
The following tour starts and ends at Tokyo Station, contrasting the Tokyo of old with the Tokyo of new. In this tour you will visit the following major destinations:
You will need to get a Suica or PASMO fare card worth at least ¥3000 to be safe. Either type of fare card can be obtained at the nearest train station.
If you have a Japan Rail Pass when entering the country, you can just walk through the barriers when entering and exiting the JR system and flash your pass to the guard. However, you should purchase a ¥3000 fare card in any case.
You can do this itinerary on any day except Mondays, Fridays and major holidays, when the East Gardens are closed.
 Begin: Tokyo Station (東京)
Time yourself to arrive at Tokyo station at around 10:00. If you wish, arrive earlier to experience the end of the morning rush hour. Exit towards the Marunouchi North Exit (丸の内北口), where if you are lucky, you will see one of the many special exhibitions that are constantly put on display.
Exit the station to your left and walk until you are at the center of the exterior of the station. Here is where the first stark contrast between old and new can be seen: On one side you can see brand new skyscrapers and on the other side, the red brick facade of Tokyo Station. A multi-year construction project to restore the old Tokyo Station building to its pre-World War II appearance is scheduled to be completed in 2012.
 Imperial Palace
You will see a very wide street that proceeds straight out from the center of the station; this is Miyuki Dōri. Proceed walking down the right side of the road until you reach the moat, Wadakura-bori. After walking through what is certain to be a lot of vehicular traffic, it is a slow transition into serenity as you pass the moat and come across the Wadakura Fountain Park.
After spending a few moments at the fountains, continue across the final road, Uchibori Dōri, to the Imperial Palace Plaza. Walk around the edge of the plaza, and you will soon find everything rather calm, as the transfer into old Tokyo has been made. Standing at one of the large gravel intersections, look around and see the contrast once more.
Backtrack yourself to where you entered, and turn left, walking north on Uchibori Dōri until you reach the Ōte-mon Gate (大手門), which leads you into the public East Gardens.
Browse through the main path of the gardens, picking up a beverage from a vending machine, purchasing a gift, and if lucky, hearing the screams of the Imperial Guard practicing kendo close by.
Continuing on the main path, you will reach a flower garden, where you should be able to see a large sign pointing you to Hirakawa-mon Gate (平川門), the north exit of the East Gardens.
With your jaunt through the Imperial Palace complete, turn right as you exit Hirakawa-mon and walk a short distance to the entrance to Takebashi station (竹橋) and, using your Suica or PASMO card, take the Tokyo Metro Tōzai Line one stop to Ōtemachi station (大手町).
Follow the underground arcade towards the JR Lines until you reach Tokyo Station. Flash your Japan Rail Pass, or if you don't have a rail pass, use your Suica or PASMO card. This is a nice opportunity for a quick snack at one of the many food stands before continuing on.
 Sensōji Temple
A quick entry to Modern Tokyo can be found as you walk up to platform 4 for the northbound Yamanote Line. Here, board one of the green-colored trains that arrive every 2 to 3 minutes.
The Yamanote Line is the most prominent rail line in Tokyo, with quick service, and a loop that runs around the entire city. All announcements on the Yamanote line are in both Japanese and English, with computer monitors that show information such as connections at the next stop.
Take the Yamanote Line to Ueno (上野), then walk out and down the stairs, where you'll whip out your Suica or PASMO card once again and board the Tokyo Metro Ginza Line, taking it to the terminal stop of Asakusa (浅草).
Proceed out of Exit 1, 2 or 3, and look for the large Kaminari-mon Gate (雷門), which is your signal to the road that leads to Sensōji Temple. This road, which is Nakamise Dōri, includes a covered arcade of specialty stores and food shops. Pass these initially, and the usual crowds that form around them, and come back to visit a few upon returning.
When you get back to the area around Asakusa station, don't forget to look across the river for a look at the Golden Turd, also known as the Asahi Beer brewing factory.
From Asakusa you can glimpse at Tokyo's newest attraction - the Tokyo SkyTree. When you are ready to visit it, it's just one station away from Asakusa station on the Tobu line.
Now after a totally classic experience, it's time to head in a completely opposite direction. Enter Asakusa station and follow the signs for the Toei Asakusa Line, which is another subway line. Take any train to Shimbashi (新橋) and then transfer upstairs to the Yurikamome (ゆりかもめ) light rail line. (You'll need your Suica or PASMO card for both.)
After skimming past some skyscrapers, you will see the Rainbow Bridge on your left side. Then the train makes a 270-degree right turn and enters the bridge for the crossing into Odaiba, the man-made island that boasts a completely new scene in Tokyo.
One of the main attractions here is the Fuji TV Building. But one of the more interesting ones is the Toyota pavilion, which can be reached by getting off the Yurikamome at the first stop, Odaiba Kaihin-Koen (お台場海浜公園), then taking a nice walk on the bridge across the expressway. Eventually you will come upon the complex, a part of Palette Town, which includes Toyota, as well as a Lawson convenience store. Inside the Toyota pavilion you can test-drive new Toyota vehicles if you have an international drivers license, or simply push a button and have automated elevators and conveyors present a vehicle to you. The other end of the Yurikamome is on the other side of the complex; board it here with your Suica or PASMO card and take it a few stops to Daiba (台場) to access the Fuji building.
The Tokyo Teleport station (東京テレポート) of the Tokyo Waterfront Railway, aka Rinkai Line, is located within the vicinity of the Fuji building.
 Traveling to Shinjuku
If you've progressed at a steady pace, it should be close to dusk by the time you enter the Rinkai Line. The last stop on the tour is a place which shines with nightlife, Shinjuku.
In the past, getting from Tokyo Teleport to Shinjuku was a bit tricky depending on whether or not you had a Japan Rail Pass. Although Rinkai Line trains continue directly to Shinjuku station, you travel over two separate railways (Tokyo Teleport to Osaki on the Tokyo Waterfront Railway, then Osaki to Shinjuku on the JR Saikyo Line).
Now, it's very easy and straightforward: Use your Suica or PASMO card for this leg of the trip. Do not use the Japan Rail Pass since it is not accepted for travel over the Rinkai Line. An alternative is to obtain a regular ticket - not using a Suica or PASMO - from Tokyo Teleport to Ōsaki (¥320) where the Rinkai Line joins the JR, and then exit in Shinjuku flashing your Japan Rail Pass.
Have a bite to eat in the station, if you want, or see what kind of eateries you can find, cheap or expensive, in Shinjuku itself!
Head to the east exit of Shinjuku station to begin in front of the giant television monitor at Studio ALTA, one of Tokyo's major meeting places. If you are courageous, follow the train tracks north and attempt to plunge into Tokyo's red-light district of Kabukichō (歌舞伎町)... you'll see bright signs for it just to the right of the Shinjuku Prince Hotel.
If you've had enough, walk south to Kōshu Kaidō (甲州街道) to enjoy the panoramic views of the rest of Shinjuku at ground level overlooking the train tracks, including the large Takashiyama Times Square building.
Shinjuku is the country's busiest train hub, but don't stray in Shinjuku too late, as, like the rest of the country, train services stop at midnight!
To return to Tokyo Station, you can take the JR Chuo Line across, or do the same using the Marunouchi subway line.
If you are returning elsewhere, you can take the JR Yamanote Line, or several subway lines, including the Marunouchi, Toei Shinjuku or Toei Oedo line.
If you want to stray a bit from the route, take a moment to inhale the world's largest pedestrian crossing, which can be found at Shibuya station.
You may also choose to go from Asakusa to the new Tokyo SkyTree, and then proceed to Odaiba in the evening.