I am looking around for an above ground swimming pool, now that the sun has
come out.

Unfortunately I have a National trust property and am not allowed to put up
a "structure", so it has to be something that is (at least in theory) not
permanent.

I want something fairly large. I want to be able to exercise.

The most economic option seems to be Intex Swimming pools, for £799 for
their largest - 18 foot diameter (circular).

(see: http://www.jacksons-camping.co.uk/kidstuff/swimming.htm)

That seems like the best option, but everywhere seems to be sold out! Grr

The only other option seems to be the much more expensive - up to £5,050 for
a really big one, 33 by 15 by 4 foot. (see:
http://www.uk-swimmingpools.com/Iaso.htm)

Are there any other ideas?