Error in code

Task: Eiffel Tower - lat: 48.8582, lon: 2.2945 Great Pyramid - lat: 29.9792, lon: 31.1344 Sydney Opera House - lat: 33.8587, lon: 151.2140

Declare a function named coordinates that takes a single parameter of type String, with an external name for, a local name of location, and returns a tuple containing two Double values (Note: You do not have to name the return values). For example, if I use your function and pass in the string "Eiffel Tower" as an argument, I should get (48.8582, 2.2945) as the value. If a string is passed in that doesn’t match the set above, return (0,0)

One of the errors keeps saying i cannot assign the value of location which is a string to (double, double) but thats apart of the task isn't it?

func coordinates(for location: String) -> (Double,Double) {

    switch location {
    case "Eiffel Tower": location = (48.8582, 2.2945)
    case "Great Pyramid": location = (29.9792, 31.1344)
    case "Opera House": location = (33.8587, 151.2140)
    default: (0,0)
    }
    return location
}