The Combined Topic Particle "には"

京都にはたくさんのお寺がある。 There are a lot of temples in Kyoto.
裏庭にはニワトリがいる。 There is a chicken in the backyard.

The combined topic particle "には" is used when the topic of a sentence is a noun, usually a place noun, followed by "に". The meanings of these sentences can also be conveyed without making the place the topic of the sentence:

たくさんのお寺が京都にある。 There are a lot of temples in Kyoto.
ニワトリが裏庭にいる。 There is a chicken in the backyard.

Since Japanese is a "topic-comment" language, we hear the first two sentences more often than the last two. Here are some other examples where a noun that can be regarded as a place noun accompanies "には":

テレビの横には時計がある。 There is a clock by the TV.
私のあごにはほくろがある。 There is a mole on my chin.

The sentence structure "A には B がある" can also be used when A is not a place noun.

私には誰にも言えない秘密がある。 I have a secret which I can't tell anyone about.

Although "私" is not a place noun, I think you can understand this usage. The non-topic version of the above sentence is also understandable:

誰にも言えない秘密が私にある。 I have a secret which I can't tell anyone about.

However, the following sentence may be surprising because the corresponding non-topic sentence doesn't sound logical.

私には姉がいる。 (Correct and very natural) I have an older sister.