Montserrat?

What time's lunch? How important is five? How well do you know Barcelona?

Up, down, look around, park and unpark is three hours -- if you hustle. You've a two hour drive when you're done -- if you don't get twisted around in Barcelona.

Lunch around noon or so. Five isn't firm, we'll be meeting up with an aunt and uncle in Barcelona for a late dinner. First time to Barcelona.

It would be, at best, a very tight squeeze. You'd have to eat lunch, which in Spain is a 1-2 hour event if you sit down at a restaurant. Then drive to Montserrat. Then visit the site, including the tram up and down. Then drive to the rental drop-off (you don't say where that is). That's a lot to do in 5 hours.

You might make it work if you eat a picnic type lunch or eat casually at Montserrat. And if 5:00 is not a firm deadline (if you reserved that car only until 5:00, they may well charge you extra for a late drop off).

Thanks for the input. The plan is to get together with relatives around 9 pm for dinner so we have some wiggle room. We haven't reserved the rental yet so I'll try and push it back a bit. It looks like we'll be dropping off at Europcar's Centre de la Vila location northeast of Citadel Park.

I like the idea of a picnic rather than restaurant for lunch. At Montserrat, I'm mostly interested in the cable car ride and the geology. How's the hiking? Google maps says it should take about 40 from Montserrat-Aeri where we catch the cable car to our drop off in Barcelona? Does that seem legit?

we took the train from Barcelona to Montserrat so can't tell you if your drive time is legit. I do recall waits for cable cars etc. ...totally worth the trip, hiking is intense or easy depending on your risk level, I recall lots of insane rock climbers doing crazy climbing....

Looks like you've had some advice to steer you in the right direction. Buen viage!