The only services available here are from Ken Ewers, who will repair items once the Blood Ties quest has been completed, and Evan King, who will give the player various items at daily intervals (also only available once Blood Ties is completed).
Arefu once had more inhabitants than it does in the year 2277, but population has decreased drastically due to the inhabitants either dying or leaving to safer settlements like Megaton because of creatures, raiders and slaver attacks. Additionally, Arefu has recently become the target of attacks from The Family.
Arefu's four houses sit atop a defensible section of the remains of a bridge running across the Potomac River. Part of the overpass has collapsed, making it impossible to enter the settlement from the north. It is one of the stopping points on the trading caravan circuit, and sandbags are also deployed near its entrance to help the inhabitants fend off attackers.
An Enclave outpost can be seen after the player completes The Waters of Life, on the other section of the overpass, visible to a player looking out from the highest drop-off point. These soldiers can shoot at the player across the gap as well as be shot at themselves. However, the people in Arefu won't attempt to eliminate the outpost themselves.
There is an easter egg in the lake under Arefu. If you look east out into the lake while standing next to King's outpost you can see a dock extending from the south shore with a footlocker and a first aid box on it. Jump down (into the water, to avoid damage) and swim over to the platform. Stand on the platform and jump in the water. Swim to the bottom and out away from the platform until you reach an old car at the bottom. Next to the car is a skeleton with two cinder blocks tied to its feet. There is a silenced 10mm pistol and ammunition box lying next to him as well. This is most likely a reference to the gangster style killing and dumping of a body.
Upon first arrival at Arefu, the Lone Wanderer is greeted by a scripted grenade thrown by its "sheriff," Evan King, and he comments on how he nearly blew you up, however the grenade does not damage the player's HP.
You can pick Evan King's lock without a Karma penalty, even though it is considered trespassing.
After the quest Blood Ties, Evan King will leave his post and walk around, and the residents will come out of their houses and walk around.
Often a robot or some other Wasteland creature will spawn at the entrance, attacking the brahmin in front of the guard shack or the Merchant Caravans if they are present. Additionally, a creature may spawn inside the town itself after entering and exiting one of the buildings.
The Lone Wanderer can discover Arefu and avoid the scripted event.
If the Lone Wanderer kills people in Arefu (or if one of them dies while the Lone Wanderer is there) the others will turn hostile, but apart from Evan King they won't attack, they will simply run away from the Lone Wanderer. After killing Evan King, the Family (the vampires) in Meresti Metro Station will no longer speak to the Lone Wanderer, but they won't be hostile. Note that you can no longer trade with Karl after killing King. The only person who seems oblivious to all this is Ian West, who will remain friendly and keep the same dialogue options as before (at least if you brought him back to Arefu in the Blood Ties quest, unverified otherwise).
If you have completed the Blood Ties quest in favor of the residents of Arefu by giving blood packs to The Family, if you kill any member of The Family the residents of Arefu and The Family will turn hostile.
The West's residence, located at the north end of town, can be used as player housing.
There are some mirelurks below this location, after the Take it Back! quest, some Enclave Soldiers or Officers can be found on the other side of the broken bridge.
If the Lone Wanderer kills anyone in Arefu, everyone else there will turn hostile, unlike other settlements the people of Arefu will stay hostile indefinitely.
Just above the entrance (where the highway leaves the ground), you can see a damaged traffic sign that should read "CAREFUL," but on which the 'C' and 'L' have faded away to display "AREFU". A similar town-naming technique is used for Novac in Fallout: New Vegas.
Arefu is a small village in Romania, most well known for its proximity to the former castle of Vlad III, the prince of Wallachia, who is also known as "Dracula" and "Vlad the Impaler."