Virtually all the flights from the US to Europe are red-eye (overnight). This is so there is enough time for the plane to make the return trip back to the US in the same day. Convenient for the airlines but decidedly inconvenient for passengers. That means you often arrive in Europe (especially western Europe) very early…6–8am local time. If you fly farther east (like Rome), you can arrive mid-to-late morning. Regardless, you’re going to arrive prior to check-in.
We flew to Madrid because there was a direct flight from Charlotte. We arrived at 6:15am. We told our Airbnb host that we needed to check-in early. They told us to bring our bags by the apartment and they will keep them until they get the place cleaned. They’ll put extra people on cleaning duty so we are in “first thing.” Sounded good to me.
We arrive and take our bags by the apartment. When I asked our host how long before we can get in, he said “Check-in is 3pm”. It’s like 48 degrees outside and I made no other arrangements. I asked if he recalled our need to have the place early. Clearly, he had forgotten. We had to roam around the Madrid city centre running on 1–2 hours sleep (my wife and kids got no sleep) with it cold and drizzly outside. It was a miserable way to start our European adventure.
Fortunately, Madrid turned out to be one of my favorite cities.
What I would have done different: book an extra night at our apartment / hotel so as soon as we arrive we could go straight there and relax. Especially for a long trip like ours with lots of luggage, two kids, and no sleep, it would be worth it.