So, like in the grassy area right next to the Watergate steps? Seems fine, depending on the scale of the arch.

Large-scale monuments should say something. This one says: We couldn't think of anything original.

An arch doesn’t really speak to me. What’s something more awesome we could put there instead?

The traditional grand monuments in the West are arches and obelisks/columns. We already have an obelisk. How about a pyramid/ziggurat? After all, we have one on our money.

A donut?