OSNI 1:50,000 Discoverer Series

The 1:50,000 Discoverer series of maps published by Ordnance Survey of Northern Ireland (OSNI) consists of 18 sheets. These maps cover the whole of Northern Ireland and parts of the Republic of Ireland (the Republic is almost entirely covered by the OSi 1:50,000 Discovery Series).

Each of the blue markers on the key map below represents the centre point of a map sheet in the OSNI 1:50,000 Discoverer series. You can find out more about a specific sheet by clicking on the relevant blue marker, or by selecting from the list further down this page:

 Map sheets in the OSNI 1:50,000 Discoverer Series:

  Sheet 4

  Sheet 5

  Sheet 7

  Sheet 8

  Sheet 9

  Sheet 12

  Sheet 13

  Sheet 14

  Sheet 15

  Sheet 17

  Sheet 18

  Sheet 19

  Sheet 20

  Sheet 21

  Sheet 26

  Sheet 27

  Sheet 28

  Sheet 29