Major Story Arcs
Angel owns numerous properties all over the country. When the Defenders' latest headquarters is ruined in a battle (their brownstone in New York, which followed several other bases including Dr. Strange's house, Kyle Richmond's Long Island ranch, and the house that Hellcat grew up in in New Jersey), he offers them the use of the Aerie as their new base.
It was a very relaxed headquarters, with lots of time spent sunbathing.
They stay there until the end of the Defenders run, when the break up after the battle with the Dragon of the Moon. It was invaded several times before then, by opponents such as Manslaughter (twice!), a vine-monster, Professor Power, and others.
Angel later let X-Force use the Aerie as well.