The conditional tense is used to describe what someone would do or what would happen in the future. It can also be used to express ambitions and intentions. For example: ...
The conditional of hay (there is/there are) is habría (there would be), eg en mi ciudad ideal habría una piscina (in my ideal town, there would be a swimming pool).
Conditionals are used to express both real, likely and unreal situations. As a result, tenses used with them are not flat; they change. That is why the difference between ‘If I arrive’ and ‘If I had ...