first OTS I played was one I hosted myself, with nothing in it... I'm talking back in the times of old old client (6.x) where you had to make everything yourself etc xD
also I remember playing a server where all you could do was walk around, I dunno who hosted it, wish I was still in touch. The server was literally a house and a garden and that was it, back before map editors and map storage was even made, oh how I miss those days xD