- The Cliff House is a neo-classical style building perched on the headland above the cliffs just north of Ocean Beach. Located on the West Side of San Francisco in the city’s Outer Richmond neighborhood, the building overlooks the site of the Sutro Baths ruins, Seal Rocks, and is part of the Golden Gate National Recreation Area and operated by the National Park Service (NPS). The Cliff House is owned by the NPS; the building’s terrace hosts a room-sized camera obscura.
- Archimedean solid (Wikipedia)
In geometry, an Archimedean solid is one of 13 convex polyhedra whose faces are regular polygons and whose vertices are all symmetric to each other. They were first enumerated by Archimedes. They belong to the class of convex uniform polyhedra, the convex polyhedra with regular faces and symmetric vertices, which is divided into the Archimedean solids, the five Platonic solids (each with only one type of polygon face), and the two infinite families of prisms and antiprisms. The pseudorhombicuboctahedron is an extra polyhedron with regular faces and congruent vertices, but it is not generally counted as an Archimedean solid because it is not vertex-transitive. An even larger class than the convex uniform polyhedra is the Johnson solids, whose regular polygonal faces do not need to meet in identical vertices.