Abstract: A lightweight base frame including connectable frame members. The members are advantageously extensible. A thicker central portion of each member advantageously provides sturdiness and stability to the base frame. A cloth is suspended taunt across the frame. Once assembled, the base frame and cloth form the floor of the shelter as well as a cot. Attachable adjustable-height legs with high-traction feet further enable the user to lie comfortably and level above grade on a wide range of ground surfaces, even on rugged or sloping terrain. In a preferred embodiment, built-in leveling bubbles in the end and side frame components help adjust the base frame to level. A shelter primarily in the nature of a tent is then erected up from the base frame.