Many African countries, including Angola, Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Republic of the Congo, Côte d'Ivoire, Equatorial Guinea, Gabon, Ghana, Guinea, Liberia, Mali, Mauritania, Niger, Rwanda, São Tomé and Príncipe, Senegal, Sierra Leone, Uganda, and Zambia, require all incoming passengers to have a current International Certificate of Vaccination, as does the South American territory of French Guiana.
Every country processes visa applications at a different rate. Make sure to check the government website of the country you intend to visit to find out how fast they process visa applications. For example, visa applications from Russia to visit Canada take approximately 8 days to process, while Canadians looking to travel to India are advised to submit visa applications at least 15 days in advance.
Avoid large groups or events where crowds have gathered. Public events of any nature, including concerts and sporting events, can unexpectedly turn violent. Demonstrations and strikes are common in urban areas, may occur unexpectedly, disrupt transportation, and may escalate into violence. Check the website of the Embassy or Consulate nearest you for current information on demonstrations.
Vietnam – India passport holders can get eVisa for 30 days for $25 USD. No documentation needed. Processing takes 2 working days. India passport holders can also get VoA for 30 days or 3 months. You must get an approval letter prior to arriving in Vietnam. Approval letter costs about $10 USD. Plus, VoA fee at the airport is $25 USD. Approval letter takes 2 working days. More info at Vietnam Visa Guide.
India maintains a complicated visa processing system that begins with an in-depth online application; we highly recommend that India travelers use the services of a visa expediting company. US citizens who are traveling for tourism can obtain one of two types of visa: a single entry e-Visa (electronic visa, issued online) valid for a 30 day stay, or a 10 year multiple entry visa issued as a sticker visa on their passport. Business travelers are required to apply for a multiple entry sticker visa.
Many countries also require a photo be taken of people entering the country. The United States, which does not fully implement exit control formalities at its land frontiers (although long mandated by its legislature),   intends to implement facial recognition for passengers departing from international airports to identify people who overstay their visa.
Hungary allows Australian citizens who wish to stay for more than 90 days in the country to apply for a residence card from the regional directorate of the Office of Immigration and Nationality within 90 days of arrival and do not need to obtain a residence permit prior to arrival in Hungary (unlike most other non-EEA and Swiss foreign nationals).
Most countries in Europe do not require visas for stays of under three months. Great Britain allows Americans to stay six months before requiring a visa. Armenia and Azerbaijan require visas, which are issued on arrival, according to the website Retire-Asia.com. The website also lists which countries do not require visas for entry and those that issue visas on arrival.
Azerbaijan also strictly bans any visit by foreign citizens to the separatist region of Nagorno-Karabakh (the de facto independent Republic of Artsakh), its surrounding territories, and the Azerbaijani exclaves of Karki, Yuxarı Əskipara, Barxudarlı, and Sofulu which are de jure part of Azerbaijan but under the control of Armenia, without the prior consent of the government of Azerbaijan. Foreign citizens who enter these territories will be permanently banned from entering the Republic of Azerbaijan and will be included in their "list of personae non gratae". As of 2 September 2019, the list mentioned 852 people.