It's a neighborhood COVID PCR testing site, and they offer great free service. Your result will be ready in 10-15 minutes as you wait, or if you don't want to wait for it, you can receive it to your email account you provide.
This testing center happened to be located right behind our hotel we stayed. Our main purpose of visiting Heidelberg was to visit Christmas markets, and since we knew they currently required 2G+ standard (COVID vaccination certificate, government-issued ID and negative PCR result) for entry, we were wondering where we can get it done. We were very fortunate to find one so close by accident, and it was not too busy at the time of our visit. As we found out later at the markets, the line was very long...I would guess it would've taken about an hour before you could get tested.
It's a great public service as COVID-19 restrictions becomes even stricter around here. It's open everyday from 6:30 until 22:00. read more