Borders (synonyms: country border; example toponyms: The Northern Border) are agreed upon boundaries that mark the perimeter of a country or kingdom. They often fall on difficult to cross or easy to defend terrain features such as rivers or mountain ranges. In more fantastic worlds giant canyons, magical rifts, stormlands, or other regions may also be places a border may be located. Borders between countries may have watchtowers, border towns, border checkpoints, great walls, or minefields. Crossing a border may require official permission or documentation. There may be secret routes to cross a border that may entail underground tunnels, cliffside pathways, perilous bridges, treacherous waters, or passing through dangerous ruins, wastelands, or other locations. The surrounding lands may be borderlands or a frontier. There may be contested territories or neutral zones nearby. Borders are home to smugglers, soldiers, and traders.

When drawing borders for your fictional countries, consider the local terrain. Borders often fall along rivers or mountain ranges which are easy to defend.

How would someone legally and illegally cross a border in your world?

When designing borders consider how they came to exist. Borders may have shifted throughout history due to war or other geopolitical event. Shifting borders can mean towns, cities, and terrain features within the borderland may have multiple names. The people in this area may have nuanced and strong opinions on the political relationship of the adjacent countries and the culture of the area may be a mixed one.