Day trip to Granada from Marbella
 

We will be staying in Marbella and were planning to do a day trip to Granada to visit Alhambra. I've looked at a lot of the postings and am starting to question whether this will be doable as a day trip. I was thinking of getting the afternoon ticket to Alhambra so that we would have enough time to drive in from Marbella. From what I can tell, it looks like it would take about an hour and a half to get there. We should be able to grab a quick lunch and then visit Alhambra. Another question is, if we get the afternoon ticket which I believe starts at 2PM, and get there earlier, will we be able to go into the grounds and visit the gardens or non-ticketed areas prior to our time slot or do we need to wait until 2 to enter?

It'll take you longer to get there, I guess 40 mins from Marbella to Malaga, and then 90 mins to Granada. You will actually not enter both cities, but you'll have some spots with heavy traffic, and you may miss some access or exit, so pay attention. Once in Granada, follow signs to Alhambra and its parking lot.

It's been a few years so I don't remember details but we were staying in Marbella and went to Granada for the day. I remember it was a long day but it worked out okay.

No doubt it would be a long day. I would estimate the driving time to be at least 2 and a half hours each way. If you do go ahead, I think it would be imperative that, as you mention, you get your Alhambra tickets with an afternoon time slot to the Nasrid Palace.

For comparison, we did such a day trip, but from Nerja (much closer to Granada than is Marbella). For a 12 noon entry time, we left Nerja at around 10 AM and made it with just a little time to spare (not much!). Remember also that the Alhambra grounds are huge, and just going from the parking lot, orienting yourself, retrieving your reserved tickets and walking over to the Nasrid Palace (just one portion of the grounds) can it itself take a little while ( 20 or 30 min ?), so do not cut things too close time-wise.

The drive I would suggest is two hours each way.

At the very least the Palacio Carlos V and the two museums are free if EU passport carrying (and they are closed on Mondays).