@Matthew Guimac - I'm not that conversant with other Polar exhibits Matthew, but the 3 very large enclosures at YWP have several natural-looking lakes, undulating land and caves where the 4 other Polars can roam, in addition to the new area where Rasputin is still in isolation.
@Matthew Guimac
It doesn't look like their natural habitat really - I'd say Highland Wildlife park has a more 'realistic exhibit, but both are amazing.