As a result, whenever I go to another country the first thing I do is to try and find some decent maps of the area. With, you know, contours on them. It can be surprisingly hard.
I was so, so glad to find this.
http://earthexplorer.usgs.gov/
It's an agglomeration of most maps that are available -- you can pick the area, and then see a giant list of the types of maps that cover those coordinates. From topo maps to high resolution aerial photographs, to solar irradiance, to rainfall -- all types of interesting materials.
There are a lot of different overlays as well as older versions available. I especially recommend the 'Dufour Map' and the 'Siegfried Map' from the 19th century, the earliest official maps of the country.
It's in French, unfortunately for the Anglophone world, but they also have aerial maps dating back to the 30s under the advanced explorer.
Now, if only they had a mobile app...
streetmap.co.uk works everywhere, though, if you can stand the old-school interface:
https://mapy.cz/turisticka?x=14.1802678&y=49.9386049&z=14&so...
They have coverage of the whole Europe and an app with offline maps. They also have other map layers - Summer/Winter tourism, roadmap, physical, 19th century and one that can be printed for blind people.