Any ideas for a cheap/easy flooring solution?

[Babyplaymat]

We are looking to build a seating area in the garden, on a fairly flat grassed area.

Don't want to spend a fortune or loads of time as in the next year or so we may extend into the space.

Any ideas? I've tried Pinterest and get lots of funky looking pallet style decks, but I can't imagine them lasting very long.

If it only for the summer, this year, put down a thick bed of sand and second hand paving slabs. You might get thesescheap on Gumtree or Freecycle