The country known as the 'Land of a Thousand Lakes' is:

Concept: Countries are often given popular nicknames based on a distinctive natural or geographic feature that sets them apart from others -- a coastline shape, a climate phenomenon, or, as here, an unusually large number of natural lakes within their territory.

Application: Finland has an estimated 188,000 lakes spread across its territory -- roughly one lake for every 30 people -- making it one of the most lake-dense countries on Earth. This striking abundance of lakes is the reason Finland is widely known as the 'Land of a Thousand Lakes' (Finnish: Tuhansien jarvien maa), a title even used in Finland's own tourism promotion.

Cross-check -- the other offered countries carry different geographic nicknames:

• Italy is popularly nicknamed 'Bel Paese' (the beautiful country) for its boot-shaped Mediterranean peninsula and scenic landscape, not for its lakes.

• Scotland is known for its lochs (such as Loch Ness and Loch Lomond) within the Highlands, but its popular nickname relates to its Highland and tartan heritage rather than a 'thousand lakes' title.

• Norway is popularly called the 'Land of the Midnight Sun', a nickname tied to its extended Arctic-summer daylight rather than its lake count.

Hence, Finland is the country known as the 'Land of a Thousand Lakes'.