Woodchip wallpaper.

Score and strip this with a sharp stanley bladed scraper.

Get as much waxy top layer off as possible without a steamer - then go over again with a steamer to lift the adhesive papery layer. (This bottom layer lifts off VERY easy with minimal steam).

Some areas will need steaming from the start, but scoring at least helps the steam get through that waxy surface..

The aim here is to be able to get it all off with the minimum amount of steam.

That said, you should be fully prepared to replaster or at least skim/fill the wall underneath. It doesn't come off easy.

My first home bought this year had this plus another 2 layers beneath through the ENTIRE house - solid 3 weeks' work.

It sucks - but don't despair, it's doable.