Although not as old as some in Kyoto, the Sensoji Temple is both the oldest and most important temple in Tokyo, and is in itself a good reason to visit Asakusa.
The temple is the most visited spiritual site in the world with 30 million annual visitors and is made up of a main hall, reconstructed after damage during the Second World War and a 55 metre high Pagoda which dominates the complex.
To get to the temple you must cross the busy shopping street of Nakamise Dori, where you can buy souvenirs from fans, to woodblocks and even kimonos, as well as eating hand made noodles, tempura, etc. At the end of the street comes the temple itself, with the entrance dominated by the Kaminarimon or "Thunder Gate". Here you can see the hanging the largest paper lantern in the world, 4 meters tall and weighing 670 kg.
Bizarrely, on Kappabashi Dogugai you'll find the shops that supply nearby restaurants with replica food, to be placed on display in the windows and to entice custom!
To get here, leave the temple gardens on the left-hand side of the temple and walk some 300 metres, crossing the main road in the process. Leave your hurries behind, and take a wander through these streets.