What type of estate is known for being of indefinite duration and freely transferable?

The fee simple estate is recognized for its indefinite duration and the ability to transfer ownership freely. This type of estate represents the highest form of ownership in real property. The owner of a fee simple estate has complete control over the property and can sell, transfer, or bequeath it as they wish.

In contrast, a life estate is limited to the lifetime of the individual who holds the estate, meaning it will automatically terminate upon their death. A leasehold estate grants temporary rights to use and occupy a property but is restricted by the duration of the lease agreement. The term "condos estate" is less conventional and typically refers to ownership of individual condominium units, which may not carry the same indefinite transferability features as a fee simple estate.

Therefore, the characteristics of a fee simple estate make it the correct answer, as it allows for an indefinite duration of ownership and does not impose restrictions on its transferability.