Our plane lands at 8:30am but we can't check into our AirBnB until 3pm. Even allowing for a couple of hours to get our bags, get through customs and into the city from the airport, we're still going to have several hours we'd rather not be dragging our suitcases around town. Are there lockers or someplace secure and handy to store bags during the day? Our AirBnB is in the Alfama.