It is the oldest surviving Baha'i temple, and it's definitely worth a trip on the purple line. It is beautiful.
Rumor has it that a poor woman from the south side journeyed all the way north with a single brick to contribute all she could to its construction, which began in 1912.
The first was built in Turkestan in 1908, but torn down in 1962. As of this writing, a new temple is under construction in Chile.