May 17 & 18 and October 17 are particularly popular as rather elaborate festivals are held on these dates with omi koshi (carrying the Toshogu deity through the streets with a portable shrine) and hundreds of people parading in traditional costumes, which are stored at Toshogu Shrine. There is also a Nikko Ice and Snow Festival during the first two weeks of February near the Chuguji Shrine at Lake Chuzenji. Many ice sculptures are erected and there are fireworks and other daily events.
World Heritage Site - Nikko's 2 Shrines + 1 Temple
One of the MUST visit places when you happen to be in Japan. You really have to put aside a whole day for Nikko. It takes about 2hrs to travel from Ueno to Nikko on JR line and it's good to start early. Nikko not only attracts foreign tourists but is also a popular destination for local visitors, who visit the temples and shrines to worship, the onsens to relax and enjoy the natural beauty of the area. Ideally, you should spend 2days and 1night in Nikko, staying over at one of the hot spring resorts. As for me, I did a daytrip to visit the 2 main shrines and temple in Nikko. I'm leaving Lake Chuzenji, Kegon Falls, Senjogahara plateau, Kirifuri highland and the onsens for my next visit.
"Futarasan Shrine & Taiyuin Mausoleum"
Ancestral beliefs led to the building of Futarasan shrine (Mt. Nantai), where 3 Gods were enshrined. It's all a bit complicated and I'm still learning more about this. I got a little lost there and I thought that Futarasan is somehow connected to Taiyuin Mausoleum (for Shogun Iemitsu Tokugawa). I was surprised that the gates guarding Taiyuin are as elaborately carved as Toshogu, and was secretly pleased that the tourists have yet to swarm to Taiyuin.
The crowd gathers fast here at Rinno-ji, being the first stop for their tour of Nikko. As Rinno-ji is made up of many subordinate temples and it's grounds are large, it's impossible to see everything. Unfortunately, many areas are camera-unfriendly.