You don't unlock the hallowed tower but you can use it. I think you have to of beaten the elite four before you do this. If you talk to the karate guy to the left of Hearthrome City (Route 208), beside the honey tree, he will give you an odd keystone. Then if you go back to the tower and press A you will ba asked to place the keystone into the tower. Then you go underground and talk to 32 people (talking to shop owners doesn't count you need to have a friend to meet underground, you also can't ust keep talking to them, you have to go into your secret base, close the door, then come back out and talk again). Once you have done this go back to the tower and press A. Then a Spiritomb, at level 25, will appear. You can then catch, kill or run from it.
Hope this helps.
P.s The hallowed tower is south of Solaceon Town. If you go straight down then before you turn left to cross the water go right instead. It's right in the corner and if you go up to it without the keystone and press A it says "There is a broken, crumbling tower made of stone..."
The Hallowed tower is located on route 209 of the Sinnoh region. The player can get Spirit Tomb if the use the old keystone at the Hallowed tower.
if you look at your map, you will find hallowed tower to the right of hearthome city, on route 208. keep walking to the very right and the pile of stones is the hallowed tower once you insert the odd keystone
You can find Spirtomb in the Hallowed Tower on route 209.
to catch a spiritomb Notice: all the Pokemon in your party have to be at least a lv.70
It is a place to catch the rare Pokemon Spiritomb. It is quite easy, but you must have a friend to help you get it.You must go Underground with the stone in the Hallowed Tower and talk with a friend.Go inside a Secret Base or leave the Underground then go back and talk to your friedn again. Re-peat this until you have spoke to your friend 33 times. (Check on your Trainer Card)Click A whilst facing the Hallowed Tower and you should be battling Spiritomb. If not, feel free to contact me on my message board.
The Hallowed tower is located on route 209 of the Sinnoh region. The player can get Spirit Tomb if the use the old keystone at the Hallowed tower.
Go to Solaceon Town. Then go down. You will see a big tower. It is hallowed tower. Or it is the little tower just next the other tower. It's from stone.
if you look at your map, you will find hallowed tower to the right of hearthome city, on route 208. keep walking to the very right and the pile of stones is the hallowed tower once you insert the odd keystone
You get the odd keystone from a karate guy on route 208, put it in the hallowed tower which is by the Pokemon tower right before you get to Solaceon town, talk to 32 people underground, then go to the hallowed tower and it will be there.
You can find Spirtomb in the Hallowed Tower on route 209.
Insert the Odd Keystone you got from a karate man into the broken tower (Hallowed Tower) and talk to 32 people underground. Go back and press A on the Hallowed Tower, Spiritomb will be there.
You can get a Spiritomb after you insert the Odd Keystone into the broken tower (Hallowed Tower) and talked to 32 people underground.
On the route to Socealean town , where you find the hallowed tower, there is a tower that is the burial sight for pokemon. On the top level are two ladies. One of them will give you strength. =]
After you place odd keystone in broken stone tower, making it Hallowed Tower, greet 32 people in the underground. Afterward touch it and press A.
You can find Spiritomb at Hallowed Tower Requires Odd Keystone and talking to 32 People total in Sinnoh Underground.
hallowed tower top floor
The Hallowed Tower (sometimes wrongly spelled as hollowed tomer) is a location in Pokémon Diamond where you can fight Spiritomb. You can find it south of Solacean Town.