В каких городах сохранились до наших дней средневековые городские стены?

Израиль

Pre-modern fortifications
Part of the southern section of the Chester city walls showing the base of a former drum tower and the River Dee
The Roman walls of Lugo are a UNESCO World Heritage Site
The Walls of Ston are a series of defensive stone walls, originally more than 7 kilometres (4.3 mi) long, that surrounded and protected the city of Ston, in Dalmatia, part of the Republic of Ragusa, in what is now southern Croatia.[1]

China The Great Wall of China, China - part of UNESCO site 438,[2]. This is mostly referred to the Ming Great Wall, built from 1368 to 1644, measures 8,850 km long.
China Great Wall of Qi, the oldest of the Chinese Great Walls.
China Great Wall of Qin dynasty
China Great Wall of Han dynasty (206 BC–220 AD), the longest Great Wall in history.
China Great Wall of the Jurchen Jin Dynasty (1115-1234), built to defend against northern nomadic tribes, once spanning over 2,500 kilometers long. [3]
ChinaMongolia Great Wall of the Khitan Liao dynasty
Turkey Anastasian Wall in Turkey
United Kingdom Antonine Wall in Scotland, United Kingdom - part of UNESCO site 430[4]
Italy Aurelian Walls of Rome
Croatia Walls of Ston in Croatia
Pakistan Ranikot Fort, Also called 'The Great Wall of Pakistan', second largest wall of South Asia after Kumbhalgarh fort in India
North KoreaChina Cheolli Jangseong, North Korea and China
Germany Danevirke, Germany
AlgeriaTunisia Fossatum Africae
Germany Roman limes in Upper Germania, Lower Germania and Rhaetia, Germany - part of UNESCO site 430[4]
Iran Great Wall of Gorgan in Iran, (World's second longest wall[5])
United Kingdom Hadrian's Wall in England - part of UNESCO site 430[4]
India Walls of Kumbhalgarh in Rajasthan, India
Turkey Long Wall (Thracian Chersonese)
United Kingdom Offa's Dyke between Mercia (England) and Powys (Wales)
Ukraine Serpent's Wall, the ancient walls in Ukraine
United Kingdom Wall of Severus, between Roman Britain and [not recorded]
Poland Silesia Walls, Poland
Nigeria Sungbo's Eredo, built during 800–1000 AD in Ijebu Ode in Ogun State, southwest Nigeria
Mexico Great Wall of Tlaxcala, mentioned in the history of Bernal Díaz del Castillo
Romania Trajan's Wall, in Dobruja, Romania
Romania Athanaric's Wall, Romania
United Kingdom Wat's Dyke parallel, for part of the distance, to Offa's Dyke, England:Wales.
Vietnam Long Wall of Quảng Ngãi in Quảng Ngãi, Vietnam.

Modern walls
View from the West Berlin side of graffiti art on the Berlin Wall in 1986. The wall's "death strip", on the east side of the wall, here follows the curve of the Luisenstadt Canal (filled in 1932).

France Atlantic Wall in France
Germany Berlin Wall in Germany 1961–1989 (in concrete: 1975–1989)
France Communards' Wall in the Père Lachaise Cemetery, in Paris, France
China Democracy Wall, in Beijing (1978–1979)
India Inland Customs Line 2,500 miles (4,000 km) built 1843 onward in British India
Peru Lima City Walls in Lima, Peru
Czech Republic Lennon Wall in Prague
United States Pine Grove Cemetery, second-longest contiguous stone wall in the world, in Lynn, Massachusetts
United States The Seawall in Portland, Oregon
United States Vietnam Veterans Memorial, often called the Wall
Italy Via Anelli Wall in Padua, Italy

Walls in use today

IndiaPakistan Indian Line of Control fencing
IndiaBangladesh Bangladesh–India border
IsraelWest Bank Sections of the Israeli West Bank barrier, West Bank
United Kingdom Belfast Peace Lines in Belfast, Northern Ireland, UK
North KoreaSouth Korea Korean Wall (alleged by DPRK), Korean Demilitarized Zone[6]
CeutaMorocco Ceuta border fence, in Ceuta, Autonomous city of Spain

махачкала

везде где кремль есть.

Весь Ближний восток состоит из таких построек в каком бы городе не были вы найдете их

В Москве.

Дополню предыдущий ответ Сергея К.
Изборск, Порхов, Орёл, Тула, Владимир, Ярославль,
Коломна, Дмитров, Казань.

Почти полностью:
Таллинн, Кэнафон, Конуи, Сеговия, Олите, Уруэнья.
Толедо - больше, чем наполовину
Большие куски остались:
Севилья, Комо, Бергамо
Берик апон Твид гордо и официально носит звание города, окружённого стенами, но это стены новые, 16 век.
В Риге сохранился кусочек стены, и ещё один построен заново.
В центре Лондона есть небольшой кусок ещё римской стены

Крым, Москва

Смоленск, Новгород, Псков, Москва, Рязань, Нижний Новгород наверное самые старые замки России

не интересно перечислять, по словарям (энциклопедиям) пошарь

Нижний новгород

Псков Москва Новгород