Whether Nicaragua requires a visa for entry depends on the traveller's nationality, the purpose of the visit, and the duration of stay. Generally, citizens from many countries can enter Nicaragua without a visa for short visits (usually up to 90 days) for tourism or business under the Central America-4 (CA-4) Border Control Agreement, which includes Guatemala, El Salvador, Honduras, and Nicaragua. This agreement allows for the free movement of citizens of these countries within the region.
Travellers from countries that are not part of this agreement might need to obtain a tourist visa or a visa upon arrival, depending on their nationality. Additionally, some nationalities are required to obtain a "Consulted Visa," which requires prior authorization from Nicaraguan immigration authorities before travelling.
It's important to note that visa requirements can change, so it's always a good idea to check the latest visa requirements with the Nicaraguan embassy or consulate in your country or visit their official immigration website for the most current information before planning your trip. All international travellers must have a valid passport to enter the country.