2017 AD., Germany, Federal Republic, Federal States series, state of Rhineland-Palatinate commemorative, Porta Nigra in Trier, 2 Euro, Karlsruhe mint.

Germany, Federal Republic, Federal States series, state of Rhineland-Palatinate commemorative, engravers: Frantisek Chocola (obverse) and Luc Luycx (reverse), Karlsruhe mint ("G"), 2017 AD.,
2 Euro (25,8 mm / 8,46 g), bimetallic, brass plated nickel center in a copper-nickel ring, 8,50 g. theor. mint weight, mintage 4.200.000 , axis medal alignment ↑↑ (0°) ,
Obv.: 2017 / G - Ch / RHEINLAND-PFALZ / D , front view of the Roman city gate “Porta Nigra“ in Trier, within 12 stars on the copper-nickel ring; date above, mint mark "G" and engraver´s initials "Ch" flanking, legend and country indication "D" below.
Rev.: 2 EURO / LL , map of Europe (second map type), to right 6 lines and twelve stars of Europe on the edge; engraver´s initials LL to r.
Edge: (eagle) EINIGKEIT UND RECHT UND FREIHEIT , incuse depiction and motto on a reeded edge.
Jaeger ? ; Schön ? ; KM ? .
(from circulation in 2018)

German coins of the later Federal Republic are produced at five different mints, coins from each of them can be identified by their mintmarks, A = Berlin, D = Munich, F = Stuttgart, G = Karlsruhe, J = Hamburg.

Year / Mint Mark / Mintage / Details
2017 A 6,000,000
2017 A 73,000 Proof
2017 A 68,000 In Sets only
2017 D 6,300,000
2017 D 73,000 Proof
2017 D 68,000 In Sets only
2017 F 7,200,000
2017 F 73,000 Proof
2017 F 68,000 In Sets only
2017 G 4.200.000
2017 G 73,000 Proof
2017 G 68,000 In Sets only
2017 J 6,300,000
2017 J 73,000 Proof
2017 J 68,000 In Sets only

The Porta Nigra (Latin for black gate) is a large Roman city gate in Trier, Germany. It is today the largest Roman city gate north of the Alps. It is designated as part of the Roman Monuments, Cathedral of St. Peter and Church of Our Lady in Trier UNESCO World Heritage Site.
The name Porta Nigra originated in the Middle Ages due to the darkened colour of its stone; the original Roman name has not been preserved. Locals commonly refer to the Porta Nigra simply as Porta. The Porta Nigra was built in grey sandstone between 186 and 200 AD. The original gate consisted of two four-storied towers, projecting as near semicircles on the outer side. A narrow courtyard separated the two gate openings on either side. For unknown reasons, however, the construction of the gate remained unfinished. For example, the stones at the northern (outer) side of the gate were never abraded, and the protruding stones would have made it impossible to install movable gates. Nonetheless, the gate was used for several centuries until the end of the Roman era in Trier. It serves as an entrance to town.

more on https://en.wikipedia.org/wiki/Porta_Nigra