Original: It is bound on the south by Thiruvananthapuram district , on the north by Pathanamthitta and Alappuzha , on the east by Tamil Nadu and on the west by the Arabian Sea .
Simplified: To the south is Thiruvananthapuram district , to the north is Pathanamthitta and Alappuzha , to the east is Tamil Nadu and to the west by the Arabian Sea .