That Dam (GPS: 17.96594, 102.61106) is an ancient stupa in Vientiane, Laos. Located at 140 Rue Samsenthai, its name means Black Stupa. It dates from the early Lan Xang period (1354-1707). There is a local legend attached to this stupa, that a seven-headed dragon dwelled within it. The dragon came to life to protect Vientiane during the Siamese invasion of 1828.