The lake is located around one kilometer southwest of Mühlhausen, south of the Schwanenteich pond on the Thomaswiese meadow. The Weidensee estate is located to the south. The Felchtaer stream, which flows into the Unstrut, originates from the Thomasteich.

The Thomas pond was dug in 1607 at the source of a stream. When the Thomas spring was created on a small hill to the north-east of the pond in 1901, it was additionally reinforced with karst water. This is why you can see the occasional fir fronds in the lake water today. The Thoma pond has been designated a natural monument and is owned by the Mühlhausen fishing club. The Unstrut-Werra cycle path leads from Mühlhausen directly past the pond.