Rib 2

Aortic arch

Tracheal bifurcation

Pulmonary trunk

Ligamentum arteriosum

Left recurrent laryngeal

Azygos Vein

Nerves (Cardiac and Pulmonary plexuses)

Thoracic duct
A more detailed mnemonic is "PLOT of EARTH PLLANTS"
Phrenic and Vagus Nerve

Lymph Nodes

Oblique fissure of lungs (top of it)

Thymus

Esophagus (trending right to left)

Aortic Arch (bottom of the arch)

Rib 2, Manubrium-sternal angle, T4(more specifically T4-5 disc)

Tracheal Bifurcation (Carina: Latin –like keel of boat)

Heart

Pulmonary trunk bifurcation

L2 : Left Recurrent Laryngeal (Looping under Aorta); Ligamentum Arteriosum: Connects Aortic Arch to Pulmonary. Bifurcation

Azygous vein arches over the root of the Rt. Lung and opens in SVC.

Nerve plexi: Cardiac and Pulmonary Plexus

Thoracic duct (on its way to drain into the Left Subclavian)

SVC going down


 Mnemonic:
A useful mnemonic for what passes through the sternal angle is "RAT PLLANT"