In world geography, you are asked to identify which city is the largest city in South Africa and is also very famous for its extensive gold mines.

Introduction / Context:
South Africa is often discussed in GK both for its major cities and for its mineral wealth. Among these minerals, gold has played a huge role in shaping the economy and settlement patterns. Many exam questions combine urban geography with economic activities, and this question does exactly that by asking which large South African city is especially famous for gold mining.

Given Data / Assumptions:
We know that the city in question is the largest city in South Africa by population.
The city is described as very famous for gold mines.
The answer choices include Cape Town, Johannesburg, Kimberley, and Durban.
We assume standard demographic data that identifies Johannesburg as the largest city in South Africa by population, although Pretoria and Cape Town are also important cities.

Concept / Approach:
This is a two part association question. First, you must recall which city is the largest by population in South Africa. Second, you must connect that city with gold mining history. Johannesburg is known as the heart of the Witwatersrand gold fields and grew rapidly because of gold discoveries in the late nineteenth century. Therefore, matching both the size and the mining fame clearly points to Johannesburg.

Step-by-Step Solution:
Step 1: Recall that Johannesburg is the largest city in South Africa when measured by urban population. Step 2: Remember that Johannesburg developed around the Witwatersrand gold reef, making it a major gold mining and financial centre. Step 3: Consider the other cities: Cape Town is famous for its harbour, table mountain, and parliament; Kimberley is famous for diamond mining; Durban is known for its port and beaches. Step 4: Notice that only Johannesburg fits both clues: largest city and famous for gold mines. Step 5: Choose Johannesburg as the correct answer.

Verification / Alternative check:
Demographic data from atlases and reference books list Johannesburg as having the largest metropolitan population in South Africa. Historical accounts of mineral discoveries repeatedly mention that Johannesburg grew because of gold deposits in the Witwatersrand region. Kimberley, in contrast, is always associated with diamonds, not gold. This confirmation from multiple sources supports Johannesburg as the only correct choice.

Why Other Options Are Wrong:
Cape Town: A major city and legislative capital of South Africa, known for tourism, ports, and table mountain, but not primarily for gold mines.
Kimberley: Famous for its Big Hole and diamond mining, not for being the largest city or a gold mining centre.
Durban: A coastal city famous for its port on the Indian Ocean and beaches; it is not the largest city and is not strongly identified with gold mining.

Common Pitfalls:
Students sometimes confuse Kimberley with gold because both diamonds and gold are precious minerals. Others assume Cape Town is the largest city because it is well known as a tourist destination. To avoid confusion, remember a simple association: Johannesburg equals gold and large city; Kimberley equals diamonds; Cape Town equals port and tourism; Durban equals port and beaches.

Final Answer:
The largest South African city famous for gold mines is Johannesburg.