Watch This When You’re High - How Do They Build Underwater Tunnels?
Shout out to @bubbalinkz for this suggestion.
Humans have evolved and learned to do some pretty incredible things. Especially in terms of engineering. And architecture. We may not be capable of building the pyramids today, but I doubt those Egyptians (aliens) could build the Holland or Ted Williams Tunnel.
Or the “Channel Tunnel”, which connects England and France under the English Channel, and spans over 31 miles long.
Keep the suggestions coming. Keep them classy. No butt stuff