Complex sentence: Geographically, "Thevara" is part of the mainland Kochi (known as Ernakulam), and mark its south-west boundary, which is connected to the water bounded western part of Kochi (known as Old Kochi or West Kochi) via bridges.
Split into simpler sentences: Geographically, "Thevara" is part of the mainland Kochi (known as Ernakulam), and marks its south-west boundary. It is connected to the water-bound western part of Kochi (known as Old Kochi or West Kochi) via bridges.