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