Taichung Bus Company
Buses run every 30 minutes from opposite the railroad station. Or you can catch the bus at the following stops:
City Government, College of Education (Normal College?), Science Museum, ChaoMa, ChungChing.
The fare to Longtan was $185 two years ago, is probably around $250 now.
Taichung Bus Company: 0800-00126, www.tcbus.com.tw.
Upon leaving the freeway in Longtan, you will be getting off near the freeway interchange, where you will not likely find taxis waiting around. 15 minutes before arriving in Longtan, call 0934-278665 and ask to be picked up, for a $250 ride up to Kunlun.

Guoguang Bus Company
Buses leave Taichung Train Station and stop at Shuinan (Chungching Road) (on the return leg, it makes 7-8 stops along that route). Buses leave Taichung Station at 06:00, and thereafter hourly, 7:30 to 20:30.
Upon leaving the freeway in Longtan, you can either get off at the first stop (100 meters from the freeway interchange) or at the downtown stop. If you get off at the downtown stop, you will find plenty of taxis waiting around. The usual fare to Kunlun Gardens is $300, but if you find a taxi with a Peace Fest sticker in the window, the rate is $250. If no such taxis are in the vicinity, then call 0934-278665 and ask to be picked up, for a $250 ride.