Vimanmek is now on many main tourist trails. Large tour buses can be seen in the parking lot throughout the day, especially in the high season. However, most of the big groups will only tour the royal mansion and not leave time to visit even a few of the many other very interesting buildings. If you want to visit the entire complex, its best to go on your own or engage a personal tour guide who can make things easy. If you want to see most of what the museum has to offer, allow at least half a day. You may want to get an early start to avoid the heat of the day.