LaQua is a whole city unto itself. There is shopping, roller coasters, water rides, shows, restaurants and more. But the best reason to go isn't any of these. It is the spa!
Underneath a roller coaster near the Tokyo Dome is this odd little building. It doesn't really look like it belongs there, but is actually part of the Tokyo Dome City district's entertainment area. The building is LaQua, a spa.
Believe it or not, there is actually a hot spring in the middle of Tokyo near the Tokyo Dome. The water is brought up from a depth of more than 1km and pumped into the spa's sauna's and hot spring pools. Plus, there are massages which can be either relaxing, or painful enough to make the hardest man cry!
For the full thing you can expect to pay about 630 Yen during the day. On the weekends and after midnight, the price skyrockets to almost 2000 Yen. So go when it opens. Plus, if you aren't comfortable with little on and in public, the crowds are smaller then.