Sweden and Finland are known for their felt courses. The surface is felt as indicated in the name and the borders are made of wood. This type of course can be quite difficult as some holes are much longer than the miniaturegolf holes.
Nowadays this type of course has grown all over Europe and it has become quite popular to play on felt.
The felt courses require more space, a typical area 1000-1500 m2. There could be some variation as the total length should be at least 180 metres, while the longest courses are well above 200 metres in length.
You could also plan the construction around the landscape and area. You can also select the holes from almost 40 different types, even though all of these are not used for competition, the producer can inform which holes are approved for tournaments.
There are international tournaments played almost every year on felt courses as they are becoming more and more popular. You are allowed to stand on these courses when you play, but you should avoid walking on the lanes as it risks that you bring dirt or small stones onto the course.