Mount Fuji, Japan
The top of the tallest mountain in Japan is not a place that you would expect to find crowds. Nonetheless, they are here. Lots of them. Approximately 300,000 people climb the 12,000-foot volcano each year.
A vast majority of people climb between June and September, meaning that the trails to the summit are lined with hikers all summer long. Even getting an early start doesn't help. Climbers begin making their way to the summit at night so that they can reach the peak in time to see the sunrise.