By car: From Freiburg, heading towards Donaueschingen on the B31. At Titisee turn right towards Feldberg/Basel. Left turn after ca. 2 km towards Lenzkirch. Take the next road on the right (after ca. 500 m). After ca. 1.5 km turn left at Gasthaus Neubierhäusle into Haslachstrasse, then take the next road on the right and you will find yourself directly in front of Landhaus Thoma.
By public transport: Train station “Feldberg Bärental”, then by taxi or by foot (20 minutes to walk).