Quessing from your user name that you're in the UK, so if your mystery tree is Araucaria araucana here's some info....monkey puzzle tree will grow quite well for you (provided you are not located somewhere really extreme!)
What it requires;
Full sun to part shade
Prefers well drained loamy soil, but will tolerate a range from slighty acidic heavy clays to slightly alkaline chalky soils
Can grow to 20m tall by 9m wide in really ideal conditions, but it is slow growing and you would expect to see in your life time perhaps 5m tall by 2m wide (very dependant on local conditions)
Is a very tough robust plant with an open habit, permitting its placement at the front of a border or out in front of a border as a feature plant, still allowing you to enjoy the plants behind.
Interestingly there were seeds of this species brought to the UK as early as the 1800's and there are some impressive specimens if you have the chance visit the Monkey Puzzle avenues at Castle Kennedy Gardens, Dumfries and Galloway, and Bicton Gardens, Devon. There is also a good specimen in the Queens cottage garden area at Kew near the Larch pond.
Hope this is helpful, enjoy your tree...oh yes remember in choosing the location the foliage of this tree is sharp and spiky so if you have small kids maybe away from pathways.
__________________ Sean Trees are poems that earth writes upon the sky,
We fell them down and turn them into paper,
That we may record our emptiness.
- Kahlil Gibran |