Beloved for its historic charm, high fashion, and heavenly cuisine, Belgium is one of Europe's best open secrets for savvy travelers. Perched conveniently between the Netherlands and France, it's also just a quick two-hour Eurostar journey from London. With an area of just under 12,000 square miles, Belgium is less than half the size of the Republic of Ireland—but has more than twice as many inhabitants, about 11.5 million.