Crypta Neapolitana

Archaeological Site Ancient Roman tunnel connecting Naples and Pozzuoli

A Roman-era tunnel near Naples linking the Bay of Naples and Pozzuoli, the Crypta Neapolitana draws visitors for its archaeology and coastal viewpoints; nearby Roman remains and volcanic landscapes add context.

Main image

The Crypta Neapolitana is an ancient Roman road tunnel in Campania that linked the Neapolitan area with the Phlegraean plain and the port of Pozzuoli. It is a significant example of Roman engineering, cutting a direct route through a volcanic ridge near Naples.

The tunnel was commissioned in the late first century BC to improve communications and was part of the Roman road network serving the Bay of Naples. Sections of the original masonry and portals survive and have been documented by archaeologists.

Designed and realised in the Roman period to shorten coastal travel, the passage continued to be used in later centuries, with modifications and partial collapses affecting its condition. Excavated and studied in modern times, parts of the tunnel are visible to visitors in the Naples-Pozzuoli area.

Geographically the tunnel crosses the Posillipo/Phlegraean ridge between the city of Naples and Pozzuoli on the Bay of Naples, with entrances and archaeological remains located in the modern urban margins of the area.

  • Roman engineering: Constructed in the late first century BC as a Roman road tunnel to link the Neapolitan area with the port of Pozzuoli, it remains one of the major Roman engineering tunnels in the region.

What to See #

  • Tunnel: The tunnel itself, carved through tuff and volcanic rock, forms the main archaeological feature and runs between two ancient portals still visible in places.
  • Portals and masonry remains: Lower stretches and portals where the Roman masonry survives are archaeological points of interest and can be viewed in the Naples-Pozzuoli area.
Crypta Neapolitana
40.8296, 14.2176

How to Get to Crypta Neapolitana #

Drive: The Crypta Neapolitana (Grotta di Seiano / the Neapolitan crypt region) is on the Posillipo headland near Naples. From central Naples it is only a few kilometres (around 4-7 km) to Posillipo; drive along Via Posillipo or the seafront roads and follow signs for the Parco Archeologico del Pausilypon / Grotta di Seiano.

Public transport: Take Naples’ Line 2 metro to Mergellina and then a short local bus or a 15-25 minute walk uphill toward the Pausilypon/Posillipo archaeological area where the Crypta is located. Local buses also serve the Posillipo area from central Naples.

Best Time to Visit Crypta Neapolitana #

Visit in spring or autumn for milder temperatures and fewer visitors; summer brings heat and higher tourist numbers so go early in the day to avoid crowds.

High season (crowded)
Jun-Aug · ~25-32°C (Naples area)
Most tourists in Naples - the site can be busier; plan early visits to avoid crowds and heat.
Shoulder seasons (best)
Apr-Jun / Sep-Oct · ~15-25°C
Milder temperatures and fewer visitors make these months pleasant for exploring the tunnel and surrounding archaeological sites.
Winter (quiet)
Nov-Mar · ~5-15°C
Cooler and quieter - fewer tourists but check opening times and local schedules.

Weather & Climate near Crypta Neapolitana #

Climate

Temperate climate with warm summers (peaking in August) and cold winters (coldest in January). Temperatures range from 5°C to 30°C. Moderate rainfall (960 mm/year).

Air Quality: AQI 54 Moderate
Best Time to Visit
JulyJuneAugust
Temperature & Rainfall
Temperature Range
41°
Warmest Month
-4°
Coldest Month
Monthly Conditions

January

January is the coolest month with highs of 13°C and lows of 5°C. Significant rainfall (102 mm) and partly cloudy skies.

53 Acceptable

Comfort

Feels Like Cold
C
Temperature
13°
85%
Humidity
Very Humid

Weather

102 mm
Rainfall
2.6 m/s
Wind
Calm
0.2
UV Index
Low
9.5h daylight

February

February is cold with highs of 13°C and lows of 5°C. Regular rainfall (85 mm) and partly cloudy skies.

55 Acceptable

Comfort

Feels Like Cold
C
Temperature
13°
83%
Humidity
Very Humid

Weather

85 mm
Rainfall
2.9 m/s
Wind
Calm
0.4
UV Index
Low
10.5h daylight

March

March is cool with highs of 16°C and lows of 7°C. Moderate rainfall (79 mm) and partly cloudy skies.

69 Good

Comfort

11°
Feels Like Cool
11°C
Temperature
16°
81%
Humidity
Very Humid

Weather

79 mm
Rainfall
2.9 m/s
Wind
Calm
0.8
UV Index
Moderate
11.8h daylight

April

April is cool with highs of 18°C and lows of 9°C. Regular rainfall (86 mm) and partly cloudy skies.

69 Good

Comfort

13°
Feels Like Cool
13°C
Temperature
18°
77%
Humidity
Very Humid

Weather

86 mm
Rainfall
2.8 m/s
Wind
Calm
1.2
UV Index
High
13.1h daylight

May

May is cool with highs of 23°C and lows of 13°C. Moderate rainfall (50 mm).

85 Excellent

Comfort

18°
Feels Like Cool
18°C
Temperature
13° 23°
71%
Humidity
Very Humid

Weather

50 mm
Rainfall
2.5 m/s
Wind
Calm
1.7
UV Index
Very High
14.3h daylight

June

June is mild with highs of 26°C and lows of 17°C. Light rainfall and mostly sunny skies.

93 Ideal

Comfort

22°
Feels Like Mild
22°C
Temperature
17° 26°
63%
Humidity
Humid

Weather

26 mm
Rainfall
2.5 m/s
Wind
Calm
2.1
UV Index
Extreme
14.8h daylight

July

July is warm with highs of 29°C and lows of 19°C. The driest month with just 21 mm and clear sunny skies.

95 Ideal

Comfort

24°
Feels Like Warm
24°C
Temperature
19° 29°
58%
Humidity
Humid

Weather

21 mm
Rainfall
2.3 m/s
Wind
Calm
2.2
UV Index
Extreme
14.6h daylight

August

August is the warmest month with highs of 30°C and lows of 19°C. Moderate rainfall (36 mm) and clear sunny skies.

93 Ideal

Comfort

25°
Feels Like Warm
25°C
Temperature
19° 30°
58%
Humidity
Humid

Weather

36 mm
Rainfall
2.2 m/s
Wind
Calm
1.9
UV Index
Very High
13.6h daylight

September

September is mild with highs of 26°C and lows of 16°C. Regular rainfall (86 mm) and mostly sunny skies.

85 Excellent

Comfort

21°
Feels Like Mild
21°C
Temperature
17° 26°
67%
Humidity
Humid

Weather

86 mm
Rainfall
2.2 m/s
Wind
Calm
1.2
UV Index
High
12.3h daylight

October

October is cool with highs of 22°C and lows of 13°C. Significant rainfall (126 mm).

69 Good

Comfort

17°
Feels Like Cool
17°C
Temperature
13° 22°
75%
Humidity
Very Humid

Weather

126 mm
Rainfall
2.3 m/s
Wind
Calm
0.7
UV Index
Moderate
11.0h daylight

November

November is cool with highs of 17°C and lows of 9°C. The wettest month with heavy rain (149 mm) and partly cloudy skies.

65 Good

Comfort

13°
Feels Like Cool
13°C
Temperature
17°
83%
Humidity
Very Humid

Weather

149 mm
Rainfall
2.5 m/s
Wind
Calm
0.3
UV Index
Low
9.8h daylight

December

December is cool with highs of 14°C and lows of 6°C. Significant rainfall (114 mm) and partly cloudy skies.

55 Acceptable

Comfort

10°
Feels Like Cool
10°C
Temperature
14°
85%
Humidity
Very Humid

Weather

114 mm
Rainfall
2.9 m/s
Wind
Calm
0.2
UV Index
Low
9.2h daylight

Nearby Attractions to Crypta Neapolitana