C.B.
Maybe put a pad by the window so he can lay down and still look out? Or a comfy chair? If he is just sitting there he may eventually fall asleep. If not, you are at least getting some quiet time without him even if he does not sleep. Maybe just tell him that he has to stay in his room but he can either sleep or relax by the window. My oldest napped until 3, the younger one stopped at about 2.5 since there was a fun toddler in the house to stay awake for. He may be getting to the end of his naps, but if you can continue the quiet time in his room he should be getting some down time if not true sleep.