7 Ancient Wonders of Middle Earth

[webwizard333]

I saw a show on Discovery a while back about the seven ancient wonders of the world, and that got me thinkning. What were the seven ancient wonders of Middle Earth? This list, as ours is, is limtied only to structures, so the one ring and the Silmarrils don't count. Also, include why.

I haven't finished mine yet, but so far I've chosen
1-Gondolin
For me, this city represents the strongest fortress to be raised up against Melkor during the war against him. It was a symbol of hope and defiance.
2-Isengaurd
Even the Ents could not bring this tower down. A hollowed out volcano, perfectly smoothed sides, not even a crack.
3-Minas Tirith
The seven walled city was the main opposition Sauron faced, and it held out.
4-Angband
This is where both orcs and dragons were created. It would be very interesting to see where and how this was done.
5-Lorien (as described in The Book of Lost Tales)
It was described as a place of rest and dreams. A beutiful place to go to and stay.
6-?
7-?