When we descend to ground level, we find that both buildings are churches. The Phoenix structure, the First Christian Church (below), was designed in 1951 by Frank Lloyd Wright and constructed in the 1970s.
I think that it bears a resemblance to the building that's located near my home, St. John's Evangelical Lutheran Church, erected in 1958. My photos are below.
Like many of Wright's works, the local church is sheltered by a dramatic roof formed from folded planes.
It features stained glass in abstract patterns.
It uses natural wood and stone in geometric forms. But there's not a huge monumental front door, just a modest entry on a human scale.