Revolution opens every now and again for special occasions. Usually a few times a year, and for a span of a few days.

Nexus is very similar in concept, however Nexus has "themes" attached to it. An entire unique set of rooms is created when Nexus opens, whereas Revolution has one singular look.

Club Crypt is another building that opens only at select time(s). It opens during Halloween, and like Revolution, has a a singular look (at least for the past 2 years).

When open, each of these buildings contain exclusive, limited-time items for sale (hats, furniture, mounts, etc.) that players usually get pretty excited about.