Turnshoes
Turnshoes are an ancient method of shoe construction. Examples date back at least 1000 years in archeological digs in Europe. The "Carolingian" below is from that time period.
In this style, the uppers are sewn inside out to a thick, single-piece sole, and the finished shoe is then "turned" rightside out, hence the name. The result is lightweight, flexible, attractive, and extremely comfortable.
They're well suited for use as house slippers, for errands around town, or light hiking shoes.