text: This note was helpful, as this is not "Wiener Tennisverein" (WTV) but a sports centre called LTM Tennis (see https://www.openstreetmap.org/way/551247967). But apart from that the note is placed on a soccer pitch, around it there are tennis pitches which are covered in winter season. The next building belongs to LTM Tennis and is a sports hall with five tennis pitches inside. And then there is the LTM Tennis building with a café etc. Since the original author didn't reply for two years and the note on it's own isn't helpful anymore I'm going to close it.