The Red Tower is named after the red color of its paint, but it is also named Hornberger Tower. It was bulit in 1430.
Also accessible by public transport. The timetables are available on www.sii.bz.it.
How to reach Dobbiaco/Toblach: https://www.drei-zinnen.info/en/dobbiaco/dobbiaco/contact-and-service/arrival-mobility.html
Parking places are available.