How to find an object (house/apartment/land) nationwide in Germany?

Ah, thanks hampshire, I had never noticed the free text field "Eigene Suchkriterien" in the filters before!

Kaho, I see it exactly the same way (Naturparadies). To put it bluntly, no neighbors, no roads/rails/airport, but doctor/pharmacy/Aldi reachable within 5 minutes on foot, with a nice view of a lake/sea/mountains

Exaggeratedly put, no neighbors, no roads/tracks/airport, but doctor/pharmacy/Aldi reachable within 5 minutes on foot, with a nice view of a lake/sea/mountains

Oh God, hopefully you don’t die before you find the egg-laying wool-milk-sow.

I would proceed differently. Choose one (or more) regions that you like landscape-wise (that seems to be at the top of your list). Then treat yourself to a nice vacation and get to know the region, so get in the car – preferably a camper. I wouldn’t search via portals at all, only once I knew where I want to go. The problem for you will be the wishes "seclusion" combined with "everything reachable on foot." In my opinion, that will only work on the periphery of a smaller (real) town.

Peace, no neighbors, no cars, everything within walking distance excludes each other.

I would look at areas in Germany to see if I like them there and then search specifically. The requirements for the property (not the location) are not high and can be found everywhere.

I also find the requirements of peace and quiet combined with walkability to shopping problematic. An apartment is then ruled out. Neighbors are never quiet.

Are there no small to medium-sized towns that you find nice spontaneously? Maybe because the historic city center is appealing and there is a lot of forest around the town?

Peace and being able to reach everything on foot, that simply doesn’t work.

A quick search yielded almost only one result that matches most of what is desired:

Scout-ID: 113023246

112 sqm, Rügen, sea access, quiet, supermarket and bakery within walking distance... for the difference to the budget, I would renovate completely, then it can become your oasis