Good morning
Let's make bridges! Materials: Styrofoam; Concrete (by the first); Acrylic paint.
The first one:
1180mm long, 420mm high, 150mm wide, aptitude 2,6%, radius 140mm; Weight approx. 15 Kg, when finished.
Pic see three postings above!
The scond one:
940mm long, 580mm high, 150mm wide, aptitude 2,6%, radius none (straight); Weight approx 3 Kg, when finished.
Needs not to be filled with concrete, will be sticking on the wall behind.

Cheers, trainmaster
with his garden layout...