They nest on open ground, usually gravel and are not all fussy about their nest, usually just a slight depression in the gravel to hold the eggs.
Their nest blends into the surrounding area and the speckled eggs look like stones so that you really have to look hard to spot it. And, this morning, Grenville and I found this nest in nearly the same place as last year's - right alongside the RR tracks. It's hard to spot the nest in the photo on the right, even when you're walking along the tracks, so the photo on the left is a close-up with 4 eggs, like last year.
And, as if nesting in plain sight wasn't interesting enough, here's another fact about kildeer. They are great scam artists and fake injury to deter intruders, usually it's a broken wing. The bird limps along dragging its wing on the ground. The moment you try to help or follow the bird, it recovers and moves on and when it senses that the nest area is safe, its broken wing "heals" and the bird flies away, calling a loud "KILL-DEE" sounding more like a jeer. We're not fooled by this faked injury, but the killdeer doesn't know we're onto its act. So, we play along and continue walking.