Pilot Adam John has visited (landed in) a total of 51 countries but have 188 countries yet to explore.

Afghanistan

Algeria

American Samoa

Angola

Anguilla

Antarctica

Antigua and Barbuda

Azerbaijan

Bahrain

Bangladesh

Barbados

Belarus

Belize

Benin

Bermuda

Bhutan

Bolivia

Botswana

British Indian Ocean Territory

British Virgin Islands

Brunei

Burkina Faso

Burundi

Cambodia

Cameroon

Cape Verde

Central African Republic

Chad

China

Christmas Island

Cocos (Keeling) Islands

Colombia

Comoros

Congo

Congo (DRC)

Cook Islands

Costa Rica

Cote D'Ivoire

Cyprus

Denmark

Djibouti

Dominican Republic

Ecuador

Egypt

El Salvador

Equatorial Guinea

Eritrea

Eswatini

Ethiopia

Falkland Islands

Faroe Islands

Fiji

French Guiana

Gabon

Gibraltar

Greenland

Grenada

Guadeloupe

Guam

Guatemala

Guinea

Guinea-Bissau

Guyana

Haiti

Hong Kong

Hungary

India

Indonesia

Iran

Iraq

Israel

Jersey

Johnston Atoll

Jordan

Kazakhstan

Kenya

Kiribati

Korea

Kosovo

Kuwait

Kyrgyzstan

Laos

Latvia

Lebanon

Lesotho

Maldives

Mali

Malta

Marshall Islands

Martinique

Mauritania

Mauritius

Mayotte

Mexico

Micronesia

Midway Islands

Moldova

Monaco

Mongolia

Montserrat

Morocco

Morocco

Mozambique

Myanmar

Netherlands Antilles

New Caledonia

Nicaragua

Niger

Nigeria

Niue

Norfolk Island

North Korea

Northern Mariana Islands

Oman

Pakistan

Palau

Palestine

Panama

Papua New Guinea

Paraguay

Peru

Philippines

Rwanda

Saint Helena

Saint Lucia

Saint Pierre and Miquelon

Saint Vincent and The Grenadines

Samoa

Sao Tome and Principe

Saudi Arabia

Senegal

Serbia

Seychelles

Sierra Leone

Singapore

Solomon Islands

Somalia

South Africa

South Korea

South Sudan

Sri Lanka

Sudan

Suriname

Syria

Taiwan

Tajikistan

Tanzania

Timor Leste

Timor-Leste

Togo

Tonga

Trinidad and Tobago

Tunisia

Turkmenistan

United Arab Emirates

Uruguay

Uzbekistan

Vanuatu

Venezuela

Vietnam

Virgin Islands, U.S.

Wake Island

Wallis and Futuna

Western Sahara