Bubbles characterize all asset markets. A bubble is an irrational over-investment in one particular sector or economy. But what is particularly interesting about property markets is that its cycles, its bubbles and depressions are (unlike the stock market) so smoothly predictable.
Buying in unfamiliar countries can present special difficulties. The problem isn't finding the right price, because most markets are sufficiently well-organized even for a foreigner to find a good prices.
The collapse of the US housing market bubble emphasizes how important it is to figure out what property is really worth, from a fundamental perspective. Make sure you're not over-paying!
50 years ago the correlations between property prices and the business cycle (fluctuations in GDP growth, interest rate changes, etc) began to be explored by economists. The question: What really explains changes in property prices?