- "Pale Death beats equally at the poor man's gate and at the palaces of kings."
The Brandenburg Gate is military-oriented and almost useless to anyone who doesn't pursue a domination victory - even the Great Scientist points are overshadowed by specialist slots from Universities, Observatories, and Public Schools. To such a player, however, it is invaluable because if built in a city with a Barracks, an Armory, and a Military Academy, all units produced will have 3 promotions upon completion. If the city also has Alhambra, newly produced units will have access to powerful tier 4 promotions such as March and Logistics. The free Great General isn't that important, since aggressive players usually have plenty of those lying around. You might use it for another Citadel in a vital battle point or to expand your borders and grab resources.
Japan can use this wonder for a unique strategy. If Rifling has not been researched yet, a city with this wonder still can train Samurai. Combined with a Barracks, Armory, and Military Academy (or even Total War from Autocracy, if you're willing to delay warmongering to such a degree), Samurai can instantly get the March promotion - one of the most useful promotions in warfare. Then, as they're upgraded to Riflemen and more advanced infantry units, they can conquer the world alongside Zeroes.
Poland also can make good use of this wonder thanks to their unique unit and unique building. The technology that unlocks Winged Hussars is a prerequisite for Military Science, and Ducal Stables provide all mounted units trained in a city with +15 XP. Winged Hussars start with Shock I, so each one trained in a city with a Barracks, Armory, Ducal Stable, and the Brandenburg Gate will be able to take Shock II, Shock III, and Blitz, March, or Mobility as its starting promotions, allowing them to push through even the tightest enemy lines.
The Brandenburg Gate is the only surviving town gate of the city of Berlin. A beautiful "triumphal arch" constructed in the Greek style in 1788-91, it features many columns and is surmounted by the "Quadriga of Victory," a statue of a chariot drawn by four horses. It stands at the end of the avenue Unter den Linden.
After World War II, Berlin was partitioned between sections controlled by the Soviet Union, and the United States and its allies. The Berlin Wall was constructed by the Soviets to keep the two parts of the city separated. The Brandenburg Gate was in a sort of a "no-man's land" between the two factions, and from 1961-1989 neither side had access. The Gate was reopened in 1989 as part of the reunification of Berlin and Germany.
Today it stands as a proud symbol of the reunified city and country, and it is visited by tens of thousands of tourists from both east and west.