Nikko was considered a sacred site for many centuries before the great warlord Shogun Ieyasu decided to build his memorial shrine there. Ieyasu was famous for ending a particularly violent, century long civil war among rival warlords and uniting the country under his control. Although he was buried there in 1616 when he died, his grandsom, Iemetsu really went to town on the place, building the most lavish complex in Japan, and adding his own shrine there as well, which outshines grandpa. The buildings undeniably have a big wow factor, although, like the Rococo period in Europe, lots of people think it's a bit over the top. Personally I think it's a lot of fun, but I really like the setting, in the mountains surrounded by ancient, soaring cedars, is the best part.