a quagmire; a bog or a difficult situation from which it is hard to escape

prefecture-level city in Hunan Province

a pool of water or a pond

Xiangtan County in Xiangtan City, Hunan

Sun Moon Lake in Nantou County, Taiwan

a pool of water that does not flow and often becomes foul or lifeless

Meitan, a county in Zunyi City, Guizhou

Yingtan, prefecture-level city in Jiangxi Province [[江西省|江西省|Jiang1 xi1 Sheng3]]

Pingtan, a county in Fuzhou City, Fujian Province

A place of extreme danger or a hostile environment; literally a dragon's pool and tiger's den.

Longtan district of Jilin city, Jilin province

Longtan district of Jilin city [[吉林市|吉林市|Ji2 lin2 Shi4]], Jilin province

Longmatan district of Luzhou city, Sichuan

to sink someone to the bottom of a pond as a form of private punishment (historically used for unfaithful wives)

Longtan Ravine, a scenic area in Xixia County, Nanyang, Henan

Lintan County in Gannan Tibetan Autonomous Prefecture [[甘南藏族自治州|甘南藏族自治州|Gan1 nan2 Zang4 zu2 Zi4 zhi4 zhou1]], Gansu province

a deep pool of water or an abyss

reflection in a deep pond

a deep pit or bottomless chasm, often used figuratively

Tantui, a northern school of Chinese martial arts

Shitan township in Miaoli County, northwest Taiwan

deep and mysterious; intellectually deep or obscure

a hidden pond or pool

a pool of water that is deep

muddy water in a pool or pond

Shitan or Shihtan township in Miaoli county, northwest Taiwan

deep natural pond

bottom of a (deep) pond