You could stop by for a short 1h-visit on your way to Hakone.
Nikko is mostly famous for Toshogu Shrine, the mausoleum of Tokugawa Ieyasu, which is a UNESCO World Heritage site.
The shrine buildings are extremely fascinating and the various carvings with all their details could keep you busy all day long.
Despite their look, they actually taste delicious and are said to prolong your life, so definitely try them! It’s also known as the Kyoto of Eastern Japan, offering numerous temples, shrines and other historical structures such as Hasedera Temple, Engakuji Temple and Tsurugaoka Hachimangu Shrine.
The most famous attraction of Kamakura is the Great Buddha of Kotokuin.
A big red gate stands at the entrance of Hakone Shrine which is located right next to Lake Ashino.